Occurrence and Distribution of Mites and Ticks (Acari) of Public Health Importance on the Island of Oahu

Abstract

The Vector Control Branch of the Hawaii Department of Health has accumulated a large volume of written inspection data on pests of public health for the island of Oahu. Mite complaints provided the fifth greatest amount of arthropod pest information available, following mosquito, other fly, flea and bee complaints; and tick complaints provided the ninth greatest amount of arthropod pest information, following ants, cockroaches and centipedes. The objectives of this study were to conduct a survey of the occurrence of mite and tick complaints on Oahu over a 10-year period, determine their distribution over time, graphically compare mite and tick occurrence within and between district/areas, and correlate mite and tick occurrence and distribution with season. Mite and tick data were drawn from inspection reports from 1990 to 1999, population information was obtained from Hawaii Census and State of Hawaii Data Books, 125 district/area geographic locations were defined, and mite and tick occurrence and distribution were adjusted for population and mapped using ArcView GIS 3.2. Most mite activity was reported within the central, south and east urban districts. The south urban districts of the island showed the highest number of complaints, and the levels of mite activity were highest during the spring, summer and fall. There were a very small number of mite problems around the ports of entry, mainly the airport. The primary mite species recorded were Dermatophagoides pteronyssinus (Trouessart), the European house dust mite; Ornithonyssus bursa (Berlese), the tropical fowl mite; Glycyphagus domesticus (De Geer), the grocer’s itch mite; Pyemotes boylei Krczal, the straw itch mite; and D. farinae Hughes, the American house dust mite. The main sources of mite infestations were house dust, birds, stored food products, fiber-type furniture, dried plant materials and bean pods. Tick activity was mostly reported within the leeward urban districts. South and west urban districts showed the highest number of complaints, and the levels of tick activity were highest during the winter, summer and fall. There were very few tick problems around the ports of entry. The primary tick species identified was Rhipicephalus sanguineus Latrielle, the brown dog tick. The main sources of tick infestations were dogs that were taken into a tick infested location or poorly cared for, especially if the dog was relocated on premises, removed from the premises or died. Mite and tick activity is being maintained in urban areas by human activities. As a result, dermatitis from mite infestations is possible as well as disease transmission between dogs by ticks, especially along leeward Oahu. The results indicate that educational programs should be carried out in late winter for mites and late spring for ticks, and that residential mite and tick surveys may be concentrated in a limited number of district/areas.